Genealogical Trees?

Why is it so important from a scientific standpoint to have genealogical trees? Scientists have spent hundreds of years slaving over newer and better methods to categorize all organisms into groups. Why is it so important? Examine the different attempts over the years to create trees. How are they different and similar? How are the organisms categorized in each tree, and why is it significant? Discuss terms like kingdom, domain, etc and discuss what they mean.

The Source Of All Variety Is Mutation

On page 57, Carroll starts his discussion of how traits are worked into genes because of their selective advantage to the species. According to Carroll, selective advantages become dominant because of mutations that occur sometimes one in a billion in one organism's DNA. This mutation can lead to a successful trait that gave the organism an advantage over others. Therefore, over time, the gene became dominant in the species. Explain this process. How does one single mutation turn into a dominant trait that every member of the species has? How long does it take for these traits to spread? How many mutations must occur before the gene is seen regularly? Finally, discuss the spread of different traits and the varying ways they can spread. For example, is there a difference between the way hair color (for hiding from predators) versus immunity (to a deathly disease) spreads? Does one take longer to catch on than the other? Do they become regular traits in different ways?

Independent Convergence

Carroll believes that the strongest evidence for the process of natural selection is the idea behind independent convergence. On pages 155-163, Carroll describes more of the mathematics of mutations and why it is very credible that species can independently produce the exact same mutations. What is independent convergence and why does it happen? What is the difference between two species that have independently evolved a trait and two species that both received it from the same ancestor. What are two methods that scientists can use to determine which of these two cases happened between different species? Provide an example from the text. Finally, and most importantly, why is independent convergence among species the most convincing evidence for natural selection? (In other words, why is it more convincing to show that two species found the same solution to the same problem rather than showing one species found a solution to its problem). To answer the last part, it's necessary to explain the three recurring "ingredients" of evolution. Explaining the two independent convergences as two trials of an experiment might make it much easier to explain your argument.

Return to Bouvet Island

From page 264-266, Carroll discuses the potential causes of dwindling numbers of krill, which is used as an important source of food and feed. Among these reasons the most prominent are overfishing and temperature increase in the arctic. Explain how each of these reasons affect the krill population. Also how may these factors play in the population of icefish that were discussed in pages 19-27. Discuss how temperature rise may be catastrophic for these fish and their hemoglobin free blood.

Fitting into the World

Humans are a diverse bunch. In the section Man Against the Sun, Carroll discusses skin color in the genetic sense. Why did skin color and hair color adapt the way it did to help Europeans, Africans, Indians, Asians, and Hispanics in their respective climates? Explain what helps absorb light rays, relating back to hormones and the endocrine system. What other features could be explained by adaption to the climate? Do these also have a genetic backing? Explain.

The Evolutionary Arms Race

At the beginning of Chapter 7, Carroll discusses the Oregon rough-skinned newt, an animal which has developed the ability to produce the TTX poison. Carroll also mentions that this happens in the puffer fish as well. Why do animals such as these develop poison instead of adapting other techniques? Where else have we seen the development of poison inside a species outside of that mentioned? Where has the predator of these animals developed resistance to the poison, and what was the next step those animals took? What are some other techniques used for survial that we've learned about?

Complexity in Fruit Fly Wing Patterns

On page 208, Carroll notes that the “fruit fly Drosophila melanogastor has pale wings but its many cousins in the large family to which it belongs display a great variety of black pigment patterns”. Explain the pigment pattern and the purpose it serves. Additionally, explain how the diversity in fruit fly wing patterns are created using Figure 8.8 on page 211.